Apparatus and method for the production of mold inserts



March 1965 R. GRAEF 3,171, 69

APPARATUS AND METHOD FOR THE PRODUCTION OF MOLD INSERTS Filed Dec. 11 1961 2 Sheets-Sheet l l N V E N TO R Favou- Q9451:-

7K @2 M 4 Lmm ATTORNEYS March 2, 1965 R. GRAEF 3,171,169

APPARATUS AND METHOD FOR THE PRODUCTION OF MOLD INSERTS Filed Dec. 11 1961 2 Sheets-Sheet 2 INVENTOR PUDOLF' 6245/ MW and zm ATTORNEYS United States Patent 3,171,169 APPARATUS AND METHOD FOR THE PRODUC- TION F MGLD INSERTS Rudolf Graef, Oberhausen, Rhineland, Germany, assignor to Huttenwerk Oberhausen Aktiengesellsehaft, Oberhausen, Rhineland, Germany Filed Dec. 11, 1961, Ser. No. 158,476

Claims priority, application Germany, Jan. 31, 1%1,

H 41,600 Claims. (Cl. 22-9) This invention relates in general to foundry apparatus and in particular to a new and useful apparatus and method for the production of mold inserts.

In the casting of steel or other metals in molds in order to obtain blocks, slabs, ingots and the like, molds or chills with so-called casting hoods are used for the purpose of preventing shrinkage or the formation of so-called piping. Such casting hoods are either placed on top of the mold or they are arranged in a manner so that they project into the upper part of the mold or insert by a certain amount. These casting hoods are provided to delay, for as long a time as possible, the solidification of the metal in the upper portion of the mold after the termination of the casting procedure proper, so that the cavities or piping which are formed in the ingots due tov the shrinkage of the metal during cooling are filled with metal. In such operations it is usual that the piping is displaced upwardly and decreased in length. Liquid metal which has not been used for filling the piping in the ingot solidifies in the casting hood and forms a socalled waste head which, after solidification of the ingot, is cut away.

Prior to the present invention, measures have been employed to delay the solidification of the metal in the head of the ingot by heat evolution. For example, sheet metal inserts have been arranged in the mold and surrounded by a combustible material, such as wood, which gives otf heat when the liquid metal is cast. A disadvantage in this procedure is that the sheet metal is'subject to great therrnic stress and will not 'remain in a stable condition, and, in many instances, the melt becomes contaminated by the deformation of thesheet metal insert. In other cases, refractory or heat insulation material has been employed to delay the solidification of the metal, but such refractories are rapidly destroyed by the liquid metal and tend to contaminate these resultant ingots. Casting hoods have been provided for eliminating the disadvantages of some of the above mentioned methods, but the cost of stable-type hoods made of cast iron or hematite are prohibitive and the use of such hoods produces a gap between the casting insert and the upper edge of the mold into which liquid metal will penetrate. Known casting hood inserts have a further disadvantage in that the manufacturer has to have a large supply of such devices or the components making up the same, in order to accommodate the various sized molds. In those instances where a refractory is rammed between the molding flask and the wall of the mold, it is difficult to lift out the molding flask from the mold without damage or destruction. Various other devices and methods have been employed which have proved unsatisfactory, either due to damage caused to the insert or the mold, or the components which are employed.

In accordance with the present invention, a movable flask is suspended within a mold for the production of mold inserts. The flask is advantageously provided with walls arranged in the central part of the mold which are made of a height which is at least as high as the mold insert to be produced. The flask is adapted to be suspended within the mold and may be positioned to align 3,171,169 Patented Mar. 2, 1965 an inflatable sealing member formed thereon with a widened insert form area of the mold and inflated to form a sealing engagement with the mold wall at' suchlocation. The sealing member is advantageously inflat= able but may include any closure device to close the space between the flask and the mold wall at a location corresponding to the bottom of the insert to be formed The sealing device is advantageously a device which simultaneously fixes the flask within the mold at the prescribed insert forming location and also clamps the flask in position.

The mold insert is formed by first positioning the flask within the mold and fixing the flask in position by operating the closure device. Thereafter, a mold mass is inserted into the space between the flask and the inner Wall of the mold and brought to a hardened condition. In some instances, it is desirable to harden the insert by the use of additional agents, such as carbon dioxide, which is directed through a double wall of the flask to the moldable material of the insert.

After the insert is formed, the closure of the flask is opened and the flask is removed by lowering it into a lower portion of the mold. Thereafter, the flask which is used is lifted out of the mold for use at another location. It has been found preferable to employ an inflatable annular member at the lower end of the flask as a closure member which is inflated to define a boundary for the bottom wall of the insert to be formed and to simultaneously cause gripping engagement of the flask with the sides of the Wall of the mold. In a preferred arrangement, a hardening agent, such as carbon dioxide, is supplied through the double wall of the flask and directed outwardly through walls along the length thereof into the mass which will form the insert. 'The flask which is employed includes an outer wall configuration of a geometrical shape which is dependent on the type of mold which is to be formed. A preferable construction, however, includes a conical sheet jacket and the entire flask is preferably provided with'a suspension eyelet so that it may be maneuvered by a crane. In some instances, a rotatable platform upon which is placed a plurality of molds in association With a rocking crane for handling the flask is employed. In such an arrangement, the molds to be provided with the insert are supplied by means of an ordinary crane to the rotatable platform and the mold is then provided with a flask which is maneuvered by the crane. Thereafter, the rotatable platform is rotated and during the rotation the insert is finished.

Accordingly, it is an object of this invention to provide an improved method of forming an insert for a mold.

A further object of the invention is to provide an improved device for operation in association with a mold which includes a flask member which is maneuverable within the mold and has a closure adapted to seal the member to the mold and provide a space between the member and the mold for the casting of an insert.

A further object of the invention is to provide a flask member for use in association with a mold wherein the flask member is of a size adapted to be manipulated within the mold and includes a closure device for engaging the walls of the mold at a location below the top thereof and corresponding to the bottom of an insert to be formed.

A further object of the invention is to provide a mold including a flask member maneuverable upwardly and downwardly within said mold, said flask member having an outer wall defining an inner wall of an insert to be molded between this wall and the inner wall of the mold, and further including a sealing member adapted to engage the wall of the mold at a spaced location from the top of the 3 mold and define with the mold the bottom of the insert to be formed.

A further object of the invention is to provide a flask member which is maneuverable within the interior of a mold and includes means for directing a reaction gas between the exterior walls of the flask member and the inner walls of the mold into which an insert is to be formed.

A further object of the invention is to provide an arrangement for forming inserts for a mold including an outer mold, a flask member maneuverable within said mold, and-a crane member arranged above saidflask member for positioning the flank in respect to the mold.

A further object of the invention is to provide a flask member for a mold which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part'of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

In the drawings:

FIG. -1 is a fragmentary longitudinal section through a mold having a flask for the formationof a mold insert constructed in accordance with the invention;

FIG. 2 is an overall longitudinal section of the device indicated in FIG.'1 with the flask indicated in an inoperative lower position after the mold insert has been formed;

FIG. 3 is a schematic indication of another arrangement for forming the mold inserts; and

FIG. 4 is a top plan view of the embodiment indicated in FIG. 3 with the crane shown positioned to one side.

Referring to the drawings in particular, the invention embodied therein includes a-mold or chill generally designated 1 which in the embodiment indicated is provided with a vertically elongated lower section la-of substantially constant internal diameter and an upper section 1b of widened internal diameter, the section 1b being formed at the location where a mold insert is to be formed.

In accordance with the invention, a flask member generally designated 2 is employed in conjunction with the mold for forming an insertat the location of the upper portion 1b. The mold insert 2 advantageously includes an outer side wall 20 which in the present embodiment is made frusto-conical but which is normally made'to a configuration depending upon the requirements of the insert to be formed. The flask also includes a flat top wall 2b and a flat bottom Wall 2d to which is'secured an annular member 2e having an annular channel 5. An inner wall 2a is provided at a spaced location from the top 2b and side wall 20. The height of the side wall 2c is'made to a height corresponding to the height of the insert produced and in this instance extends from a location adjacent a ledge portion of the mold to the top wall 1d thereof.

The side wall 2c of the flask 2 forms a space with an interior wall 1e and the bottom wall 1c of the mold in which an insert 3 is to be produced. In 'FIG. 1 the insert 3 is already indicated as being formed by an ordinary forming-mass which is filled inthe space indicated.

A feature of the invention is that theflask 2 is provided with a closure device which in the embodiment indicated includes an annular resilient member 4 which may be inflated through a conduit 8 under the control of the valve 8a. Inflation of the member 4 causes sealing of the flask 2 to the wall of the mold immediately adjacent the ledge portion 1c and also accurately positions the flask and secures the flask 2 in relation to the mold 1.

While a double wall flask is not absolutely essential in the present embodiment, the doublewall forms a conduit for the passage of a hardening'agent, for example, carbon dioxide, provided when the form mass is of a nature which is bound, for example, by water glass and therefore can be hardened or cured with carbon dioxide. The carbon dioxide is supplied through a supply line 7 having a valve 7a and is directed tothe spaces between the inner wall 2a and the outer walls 2b and 2c and through openings 6 formed in the outer Wall 20.

The flask 2 is advantageously provided with an upstanding member 12 having an eyelet or ear 9 at its upper end provided for suspension on a hook 14 of a crane 11. When it is desired to produce the insert 3, the mold 1 is either placed over the flask 2 or the flask 2 is lowered into the mold by means of the crane 11. The flask 2 is adjusted along the height of the interior of the mold and when correctly positioned (such as by aligning the top wall 21) with the wall 1d, or some marking on the side wall 2c with the top wall 1d), the member 4 is inflated by means of compressed air supplied through the conduit 8 to seal the lower edge of the flask to the mold at the upper end of the mold portion 1a. Beside sealing the flask to the mold, the inflatable member 4 also anchors the flask in its oriented position.

The mass of material is then directed into the space between the walls 1e, 10 and 2c and the hardening or cur= ing of the mass is accelerated by supplying carbon dioxide or another hardening agent through the conduit 7 and out through the hole 6 After the hardening has taken place, the inflatable mem her 4 is deflated and the crane is operated to lower the -flask2 to the bottom-of the mold 1 as indicated in FIG. 2

Thereafter, the mold 1, together with the insert 3, can be connection with the making of a new insert with the same or another mold 1.

In FIGS. 3 and 4, a rotatable platform 10 is provided for accommodating a plurality of molds 1. In this manner many inserts 3 may be manufactured rapidly in a simple manner by manipulating the flask 2 with the crane '11. 7

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may beembodied otherwise without departing from such principles.

What is claimed is: p

l. A device for the production of mold inserts in a mold comprising an elongated mold liner and a flask member having a side wall of a size comparable to the size of the interior walls of the inserts to be formed, said flask being of a size to be positioned in said mold liner and to be movable upwardly and downwardly therein, and an inflatable closure and mold positioning member on said flask inflatable to engage with the interior walls of the mold at a location at the bottom of the insert to be formed and to seal the flask to the mold at such location and to position and support the flask without additional holding means.

2. A device according to claim 1, including means on the upper end thereof for holding said member for ma nipulation by a lifting device.

.3. A device according to claim 1, wherein said flask is of double wall construction.

4. A device according to claim 3, including means for circulating fluid through said double wall construction and directing it outwardly into the space in which the insert is to be formed.

5. An apparatus for the production of mold inserts including an elongated mold liner having an internal bore with the upper portion thereof of a widened diameter, a, flask member movable upwardly and downwardly in the interior of said liner, said flask member having an exterior wall of a dimension comparable to the interior dimension of an insert to be formed, and an inflatable member carried by said flask, said inflatable member being expandable by inflation to engage the interior Wall of said mold and to seal said flask member to said mold and to support said flask member on the interior wall of said mold, the exterior of said flask member and the interior wall of said 5 mold defining therebetween a space for the formation of the insert above the location of said inflatable member.

6. An arrangement according to claim 5, including a crane disposed above said mold and having means for connecting said flask for maneuvering said flask within said mold.

7. A device according to claim 6, including a rotatable table and a plurality of molds mounted on said table.

8. An apparatus for the manufacture of ingot mold inserts in an ingot mold, comprising a molding flask member of the same height as the ingot mold insert to be produced, said flask member being freely movable in the ingot mold, a closure connected to said flask member in the region of its lower edge which closes the interval between the flask member and the ingot mold wall, characterized in that the closure fixes the molding flask member in the ingot mold and includes an inflating body and a tube for supplying a pressure agent connected to said inflating body, said inflating body being expandable by the pressure agent into sealing and flask member supporting engagement with the ingot mold, said molding flask member including a jacket provided with a plurality of apertures for the introduction of a hardening agent from the exterior walls of said flask member into the ingot mold insert being produced.

9. A method of forming an insert for a mold comprising lowering a flask member having an exterior wall of a diameter corresponding to the interior diameter of the insert to be formed into the mold, sealing and simultaneously fixing the flask member to the mold by the adhesion of the sealing means to the wall at a location at the bottom of the Wall of the insert to be formed, and thereafter pouring the material to form the insert into the mold and permitting it to harden and accelerating the hardening by directing a fluid through the walls of the member inserted into the mold into the material forming the insert.

10. A device for the production of mold inserts in a mold comprising a flask member having a side wall of a size comparable to the size of the interior walls of the inserts to be formed, said flask being of a size to be positioned in said mold and to be movable upwardly and downwardly therein, and an inflatable closure and mold positioning member on said flask inflatable to engage with the interior walls of the mold at a location at the bottom of the insert to be formed to seal the flask to the mold at such location and to position and support the flask without additional holding means, said flask including a lower annular channel member, said inflatable closure and mold positioning member including an annular inflatable member disposed in said channel, and means for directing an inflation fluid to said member.

References Cited by the Examiner UNITED STATES PATENTS 1,446,223 2/23 Thompson et a1. 25-128 1,636,243 7/27 Rasmussen 25-127 1,762,125 6/30 Perry et al. 22-21 2,763,910 9/56 Braatelieh 25-128 3,077,646 2/63 Tigerschiold 22-147 3,100,919 8/63 Vayda 22-9 FOREIGN PATENTS 638,667 3/62 Canada. 1,262,217 4/61 France.

778,039 7/57 Great Britain.

848,386 9/60 Great Britain.

885,436 12/61 Great Britain.

WILLIAM J. STEPHENSON, Primary Examiner.

MARCUS U. LYONS, MICHAEL V. BRINDISI,

Examiners. 

1. A DEVICE FOR THE PRODUCTION OF MOLD INSERTS IN A MOLD COMPRISING AN ELONGATED MOLD LINER AND A FLASK MEMBER HAVING A SIDE WALL OF A SIZE COMPARABLE TO THE SIZE OF THE INTERIOR WALLS OF THE INSERTS TO BE FORMED, SAID FLASK BEING OF A SIZE TO BE POSITIONED IN SAID MOLD LINER AND TO BE MOVABLE UPWARDLY AND DOWNWARDLY THEREIN, AND AN INFLATABLE CLOSURE AND MOLD POSITIONING MEMBER ON SAID FLASK INFLATABLE TO ENGAGE WITH THE INTERIOR WALLS OF THE MOLD AT A LOCATION AT THE BOTTOM OF THE INSERT TO BE FORMED AND TO SEAL THE FLASK TO THE MOLD AT SUCH LOCATION AND TO POSITION AND SUPPORT THE FLASK WITHOUT ADDITIONAL HOLDING MEANS. 